An Image Analysis Technique For Constructing Isostatics From Isoclinics In Photoelasticity


Using photoelasticity, isochromatic and isoclinic fringe patterns can be generated in a model specimen with an applied load. The isochromatic fringes are related to the difference between the two principal stresses and the isoclinics give the direction of the principal stresses of any point in the model. However, the isoclinics give the principal stress directions in a form that is not well suited for direct interpretation. A more useful representation is the isostatic or stress trajectory diagram where the principal stresses are tangent or normal to the isostatic lines at each point. Since the isoclinic patterns identify the direction of the principal stresses, therefore the isostatic diagram can be constructed directly from the composite isoclinic pattern. Usually this method is done by hand and involves some tedious curve fitting techniques. This paper describes the implementation of a computer program that we developed to carry out this procedure efficiently. The image of the isoclinic pattern is digitized into a database using video processing equipment and used as input to the program. The output of the program is a diagram showing the isostatic pattern.

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Publication Title

Proceedings of SPIE - The International Society for Optical Engineering



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Article; Proceedings Paper



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0027837290 (Scopus)

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